Nyob rau hauv silicon carbide ib qho kev loj hlob siv lead ua txheej txheem, lub cev vapor thauj yog tam sim no mainstream industrialization txoj kev. Rau txoj kev loj hlob PVT,silicon carbide hmoovmuaj kev cuam tshuam loj rau txoj kev loj hlob. Tag nrho cov parameter ntawmsilicon carbide hmoovncaj qha cuam tshuam qhov zoo ntawm ib leeg siv lead ua kev loj hlob thiab cov khoom hluav taws xob. Hauv cov ntawv thov kev lag luam tam sim no, feem ntau sivsilicon carbide hmoovtxheej txheem synthesis yog tus kheej-propagating high-temperature synthesis method.
Tus kheej-propagating high-temperature synthesis method siv qhov kub thiab txias los muab cov reactants pib thaum tshav kub kub los pib cov tshuaj tiv thaiv, thiab tom qab ntawd siv nws tus kheej cov tshuaj tiv thaiv tshav kub kom tso cai rau cov tshuaj unreacted mus ua kom tiav cov tshuaj tiv thaiv. Txawm li cas los xij, txij li cov tshuaj tiv thaiv ntawm Si thiab C tso tawm cov cua sov tsawg, lwm cov reactants yuav tsum tau ntxiv los tswj cov tshuaj tiv thaiv. Yog li ntawd, ntau tus kws tshawb fawb tau npaj ib txoj kev txhim kho tus kheej-propagating synthesis ntawm lub hauv paus no, qhia tus activator. Tus kheej-propagating txoj kev yog kuj yooj yim rau siv, thiab ntau yam synthesis tsis yooj yim rau stably tswj. Loj-scale synthesis ua tau raws li cov kev xav tau ntawm industrialization.
Thaum ntxov li 1999, Bridgeport siv tus kheej-propagating high-temperature synthesis txoj kev los ua ke.SiC hmoov, tab sis nws siv ethoxysilane thiab phenol resin ua raw khoom, uas yog kim heev. Gao Pan thiab lwm tus siv high-purity Si hmoov thiab C hmoov ua raw khoom los ua keSiC hmoovlos ntawm high-temperature cov tshuaj tiv thaiv nyob rau hauv ib tug argon cua. Ning Lina npaj loj-particleSiC hmoovlos ntawm theem nrab synthesis.
Qhov nruab nrab zaus induction cua sov rauv tsim los ntawm Lub Tsev Haujlwm Saib Xyuas Kev Tshawb Fawb Thib Ob ntawm Tuam Tshoj Electronics Technology Group Corporation sib npaug sib xyaw cov hmoov silicon thiab carbon hmoov nyob rau hauv ib qho piv txwv stoichiometric thiab muab tso rau hauv graphite crucible. Covgraphite crucibleyog muab tso rau hauv qhov nruab nrab zaus induction cua sov rau cua sov, thiab qhov kub hloov pauv yog siv los ua ke thiab hloov cov theem qis thiab kub-kub theem silicon carbide feem. Txij li thaum qhov kub thiab txias ntawm β-SiC synthesis cov tshuaj tiv thaiv nyob rau hauv qis-kub theem yog qis dua lub volatilization kub ntawm Si, lub synthesis ntawm β-SiC nyob rau hauv lub tshuab nqus tsev siab yuav zoo xyuas kom meej tus kheej-propagation. Cov txheej txheem ntawm kev qhia argon, hydrogen thiab HCl roj nyob rau hauv lub synthesis ntawm α-SiC tiv thaiv lub decomposition ntawmSiC hmoovnyob rau hauv qhov kub-kub theem, thiab tuaj yeem txo cov ntsiab lus nitrogen hauv α-SiC hmoov.
Shandong Tianyue tsim lub cub hluavtaws, siv cov roj silane ua cov khoom siv silicon thiab cov hmoov carbon raws li cov khoom siv raw. Tus nqi ntawm cov khoom siv roj tau qhia tau hloov kho los ntawm ob-kauj ruam synthesis txoj kev, thiab qhov kawg synthesized silicon carbide particle loj yog nruab nrab ntawm 50 thiab 5 000 um.
1 Tswj yam ntawm cov txheej txheem hmoov synthesis
1.1 Cov nyhuv ntawm cov hmoov particle loj ntawm kev loj hlob siv lead ua
Qhov loj me me ntawm silicon carbide hmoov muaj qhov cuam tshuam tseem ceeb ntawm kev loj hlob ib leeg zuj zus. Kev loj hlob ntawm SiC ib leeg siv lead ua los ntawm PVT txoj kev yog ua tiav los ntawm kev hloov cov molar piv ntawm silicon thiab carbon nyob rau hauv cov roj theem tivthaiv, thiab cov molar ratio ntawm silicon thiab carbon nyob rau hauv lub roj theem tivthaiv muaj feem xyuam rau cov particle loj ntawm silicon carbide hmoov. . Tag nrho cov siab thiab silicon-carbon piv ntawm kev loj hlob system nce nrog qhov txo qis ntawm qhov loj me. Thaum cov particle loj txo los ntawm 2-3 hli mus rau 0.06 hli, qhov sib piv silicon-carbon nce ntawm 1.3 mus rau 4.0. Thaum cov khoom me me rau qee qhov, Si ib nrab siab nce, thiab ib txheej ntawm Si zaj duab xis yog tsim nyob rau saum npoo ntawm cov siv lead ua loj hlob, inducing gas-kua-khoom loj hlob, uas cuam tshuam rau polymorphism, point defects thiab kab defects. hauv crystal. Yog li ntawd, qhov loj me me ntawm high-purity silicon carbide hmoov yuav tsum tau tswj kom zoo.
Tsis tas li ntawd, thaum qhov loj ntawm SiC hmoov cov khoom me me, cov hmoov decomposes sai dua, uas ua rau kev loj hlob ntau dhau ntawm SiC ib leeg muaju. Ntawm ib sab, nyob rau hauv ib puag ncig kub ntawm SiC ib leeg siv lead ua kev loj hlob, ob txheej txheem ntawm synthesis thiab decomposition yog ua tiav ib txhij. Silicon carbide hmoov yuav decompose thiab tsim cov pa roj carbon nyob rau hauv cov roj theem thiab cov khoom theem xws li Si, Si2C, SiC2, uas ua rau carbonization loj ntawm polycrystalline hmoov thiab tsim cov carbon inclusions nyob rau hauv lub siv lead ua; ntawm qhov tod tes, thaum lub decomposition tus nqi ntawm cov hmoov yog ceev ceev, cov siv lead ua qauv ntawm cov zus SiC ib leeg siv lead ua yuav hloov, ua rau nws nyuaj rau tswj qhov zoo ntawm zus SiC ib leeg siv lead ua.
1.2 Cov nyhuv ntawm hmoov siv lead ua daim ntawv ntawm cov siv lead ua loj hlob
Kev loj hlob ntawm SiC ib leeg siv lead ua los ntawm PVT txoj kev yog sublimation-recrystallization txheej txheem ntawm qhov kub thiab txias. Daim ntawv siv lead ua ntawm SiC raw khoom muaj qhov tseem ceeb ntawm kev loj hlob siv lead ua. Nyob rau hauv cov txheej txheem ntawm cov hmoov synthesis, lub qis-kub synthesis theem (β-SiC) nrog ib tug cubic qauv ntawm chav tsev cell thiab high-temperature synthesis theem (α-SiC) nrog ib tug hexagonal qauv ntawm chav tsev cell yuav mas tsim. . Muaj ntau ntau cov ntaub ntawv silicon carbide siv lead ua thiab qhov nqaim kub tswj ntau yam. Piv txwv li, 3C-SiC yuav hloov mus rau hauv hexagonal silicon carbide polymorph, piv txwv li 4H / 6H-SiC, ntawm qhov kub siab tshaj 1900 ° C.
Thaum lub sij hawm ib qho kev loj hlob siv lead ua, thaum β-SiC hmoov siv los loj hlob muaju, qhov sib piv ntawm silicon-carbon molar piv yog ntau dua 5.5, thaum α-SiC hmoov siv los loj hlob muaju, silicon-carbon molar ratio yog 1.2. Thaum kub nce, ib theem hloov pauv tshwm sim hauv lub crucible. Lub sijhawm no, qhov sib piv ntawm molar nyob rau hauv cov roj theem yuav loj dua, uas tsis haum rau kev loj hlob siv lead ua. Tsis tas li ntawd, lwm yam roj theem impurities, nrog rau cov pa roj carbon, silicon, thiab silicon dioxide, tau yooj yim tsim thaum lub sij hawm hloov cov txheej txheem. Lub xub ntiag ntawm cov impurities no ua rau cov siv lead ua ua rau microtubes thiab voids. Yog li ntawd, cov hmoov siv lead ua hmoov yuav tsum tau tswj kom meej.
1.3 Cov nyhuv ntawm cov hmoov impurities rau kev loj hlob siv lead ua
Cov ntsiab lus impurity hauv SiC hmoov cuam tshuam rau qhov tshwm sim ntawm nucleation thaum lub sij hawm siv lead ua loj hlob. Qhov siab dua cov ntsiab lus impurity, qhov tsawg dua nws yog rau cov siv lead ua kom spontaneously nucleate. Rau SiC, cov hlau tsis huv tseem ceeb suav nrog B, Al, V, thiab Ni, uas yuav raug qhia los ntawm cov cuab yeej ua haujlwm thaum ua cov hmoov silicon thiab carbon hmoov. Ntawm lawv, B thiab Al yog lub luag haujlwm tseem ceeb ntawm lub zog tsis txaus ntseeg hauv SiC, uas ua rau txo qis hauv SiC resistivity. Lwm cov hlau impurities yuav qhia ntau lub zog, ua rau cov khoom tsis ruaj khov ntawm SiC ib qho crystals ntawm qhov kub thiab txias, thiab muaj kev cuam tshuam ntau dua rau cov khoom siv hluav taws xob ntawm high-purity semi-insulating ib leeg siv lead ua substrates, tshwj xeeb tshaj yog cov resistivity. Yog li ntawd, high-purity silicon carbide hmoov yuav tsum tau synthesized ntau li ntau tau.
1.4 Cov txiaj ntsig ntawm cov ntsiab lus nitrogen hauv cov hmoov rau kev loj hlob siv lead ua
Qib ntawm cov ntsiab lus nitrogen txiav txim siab qhov kev tiv thaiv ntawm ib qho siv lead ua substrate. Cov tuam txhab lag luam loj yuav tsum tau kho cov nitrogen doping concentration hauv cov khoom siv hluavtaws raws li cov txheej txheem kev loj hlob siv lead ua thaum lub sij hawm hmoov synthesis. High-purity semi-insulating silicon carbide ib leeg siv lead ua substrates yog cov khoom lag luam zoo tshaj plaws rau cov tub rog tub rog hluav taws xob. Yuav kom loj hlob high-purity semi-insulating ib leeg siv lead ua substrates nrog siab resistivity thiab zoo heev hluav taws xob zog, cov ntsiab lus ntawm lub ntsiab impurity nitrogen nyob rau hauv lub substrate yuav tsum tau tswj nyob rau hauv ib tug tsawg theem. Conductive ib leeg siv lead ua substrates xav tau cov ntsiab lus nitrogen kom tswj tau ntawm qhov tseem ceeb.
2 Ntsiab tswj tshuab rau hmoov synthesis
Vim yog qhov sib txawv ntawm kev siv ib puag ncig ntawm silicon carbide substrates, lub tshuab synthesis rau kev loj hlob hmoov kuj muaj cov txheej txheem sib txawv. Rau N-hom conductive ib leeg siv lead ua hmoov hmoov, siab impurity purity thiab ib theem yuav tsum tau; thaum rau semi-insulating ib qho kev loj hlob siv lead ua hmoov, kev tswj nruj ntawm nitrogen cov ntsiab lus yuav tsum tau.
2.1 Powder particle loj tswj
2.1.1 Synthesis kub
Ua kom lwm cov txheej txheem tsis hloov pauv, SiC hmoov tsim los ntawm kev sib xyaw ua ke ntawm 1900 ℃, 2000 ℃, 2100 ℃, thiab 2200 ℃ tau kuaj thiab tshuaj xyuas. Raws li pom nyob rau hauv daim duab 1, nws yuav pom tau hais tias particle loj yog 250 ~ 600 μm ntawm 1900 ℃, thiab particle loj nce mus rau 600 ~ 850 μm ntawm 2000 ℃, thiab particle loj hloov pauv loj. Thaum qhov kub thiab txias tseem nce mus txog 2100 ℃, qhov loj me ntawm SiC hmoov yog 850 ~ 2360 μm, thiab qhov nce yuav maj mam. Qhov luaj li cas ntawm SiC ntawm 2200 ℃ yog ruaj khov ntawm li 2360 μm. Qhov nce hauv kev sib xyaw ua ke ntawm 1900 ℃ muaj txiaj ntsig zoo ntawm SiC particle loj. Thaum lub synthesis kub tseem nce los ntawm 2100 ℃, qhov particle loj tsis hloov pauv lawm. Yog li ntawd, thaum lub synthesis kub yog teem rau 2100 ℃, ib tug loj particle loj tuaj yeem ua ke ntawm lub zog qis dua.
2.1.2 Synthesis sij hawm
Lwm cov txheej txheem tseem tsis hloov pauv, thiab lub sijhawm sib xyaw yog teem rau 4 h, 8 h, thiab 12 h feem. Cov tshuaj ntsuam xyuas SiC hmoov uas tau tsim nyob rau hauv daim duab 2. Nws pom tau tias lub sij hawm sib xyaw ua ke muaj qhov cuam tshuam loj rau cov particle loj ntawm SiC. Thaum lub sij hawm synthesis yog 4 h, particle loj yog feem ntau faib ntawm 200 μm; Thaum lub sij hawm synthesis yog 8 h, cov khoom cua particle loj nce loj, feem ntau faib ntawm txog 1 000 μm; Raws li lub sij hawm synthesis txuas ntxiv mus, cov particle loj nce ntxiv, feem ntau faib ntawm li 2 000 μm.
2.1.3 Kev cuam tshuam ntawm raw khoom particle loj
Raws li cov khoom siv hauv tsev silicon cov khoom tsim tau maj mam txhim kho, qhov purity ntawm silicon cov ntaub ntawv kuj tseem txhim kho ntxiv. Tam sim no, cov ntaub ntawv silicon siv hauv kev sib txuas yog muab faib ua granular silicon thiab hmoov silicon, raws li qhia hauv daim duab 3.
Sib txawv silicon raw cov ntaub ntawv tau siv los ua silicon carbide synthesis thwmsim. Kev sib piv ntawm cov khoom siv hluavtaws yog pom nyob rau hauv daim duab 4. Kev tshuaj xyuas qhia tau hais tias thaum siv cov khoom siv block silicon raw khoom, cov khoom siv silicon ntau muaj nyob hauv cov khoom. Tom qab lub silicon block yog crushed rau lub sij hawm thib ob, Si element nyob rau hauv cov khoom hluavtaws yog txo qis, tab sis nws tseem muaj. Thaum kawg, silicon hmoov yog siv rau kev sib txuas, thiab tsuas yog SiC muaj nyob hauv cov khoom. Qhov no yog vim hais tias nyob rau hauv cov txheej txheem ntau lawm, loj-loj granular silicon yuav tsum undergo deg synthesis cov tshuaj tiv thaiv ua ntej, thiab silicon carbide yog synthesized rau saum npoo, uas tiv thaiv cov sab hauv Si hmoov los ntawm kev sib txuas ntxiv nrog C hmoov. Yog li ntawd, yog tias block silicon yog siv los ua raw khoom, nws yuav tsum tau crushed thiab tom qab ntawd raug mus rau theem nrab synthesis txheej txheem kom tau txais silicon carbide hmoov rau kev loj hlob siv lead ua.
2.2 Hmoov siv lead ua daim ntawv tswj
2.2.1 Kev cuam tshuam ntawm qhov kub thiab txias
Kev tswj hwm lwm cov txheej txheem tsis hloov pauv, qhov sib xyaw ua ke kub yog 1500 ℃, 1700 ℃ , 1900 ℃ , thiab 2100 ℃ , thiab cov hmoov SiC generated yog kuaj thiab tshuaj xyuas. Raws li pom hauv daim duab 5, β-SiC yog av daj, thiab α-SiC yog xim sib dua. Los ntawm kev soj ntsuam cov xim thiab morphology ntawm cov hmoov hluavtaws, nws tuaj yeem txiav txim siab tias cov khoom siv hluavtaws yog β-SiC ntawm qhov kub ntawm 1500 ℃ thiab 1700 ℃. Thaum 1900 ℃, cov xim yuav sib zog, thiab hexagonal hais tshwm sim, qhia tias tom qab qhov kub thiab txias nce mus txog 1900 ℃, ib theem kev hloov tshwm sim, thiab ib feem ntawm β-SiC hloov dua siab tshiab rau hauv α-SiC; Thaum qhov kub thiab txias tseem nce mus txog 2100 ℃, nws pom tias cov khoom sib xyaw ua ke yog pob tshab, thiab α-SiC tau hloov dua siab tshiab.
2.2.2 Cov nyhuv ntawm synthesis lub sij hawm
Lwm cov txheej txheem tseem tsis hloov pauv, thiab lub sijhawm sib xyaw yog teem rau 4h, 8h, thiab 12h, feem. Cov hmoov SiC generated yog kuaj thiab soj ntsuam los ntawm diffractometer (XRD). Cov txiaj ntsig tau pom hauv daim duab 6. Lub sijhawm sib xyaw ua ke muaj qee yam cuam tshuam rau cov khoom tsim los ntawm SiC hmoov. Thaum lub sij hawm synthesis yog 4 h thiab 8 h, cov khoom hluavtaws feem ntau yog 6H-SiC; thaum lub sij hawm synthesis yog 12 h, 15R-SiC tshwm nyob rau hauv cov khoom.
2.2.3 Kev cuam tshuam ntawm raw khoom piv
Lwm cov txheej txheem tseem tsis tau hloov pauv, qhov nyiaj ntawm silicon-carbon tshuaj raug tshuaj xyuas, thiab qhov sib piv yog 1.00, 1.05, 1.10 thiab 1.15 raws li kev sim ua ke. Cov txiaj ntsig tau pom hauv daim duab 7.
Los ntawm XRD spectrum, nws tuaj yeem pom tau tias thaum qhov sib piv ntawm silicon-carbon ntau dua 1.05, ntau tshaj Si tshwm hauv cov khoom, thiab thaum qhov sib piv silicon-carbon tsawg dua 1.05, ntau tshaj C tshwm. Thaum qhov sib piv ntawm silicon-carbon yog 1.05, cov pa roj carbon dawb hauv cov khoom siv hluavtaws raug tshem tawm, thiab tsis muaj silicon dawb tshwm. Yog li ntawd, tus nqi piv ntawm silicon-carbon piv yuav tsum yog 1.05 los ua ke siab-purity SiC.
2.3 Tswj cov ntsiab lus tsis tshua muaj nitrogen hauv cov hmoov
2.3.1 Synthetic raw khoom
Cov khoom siv raw siv hauv qhov kev sim no yog cov hmoov av purity carbon thiab high-purity silicon hmoov nrog qhov nruab nrab txoj kab uas hla ntawm 20 μm. Vim lawv qhov me me me me thiab thaj chaw loj, lawv yooj yim nqus N2 hauv huab cua. Thaum muab cov hmoov sib tov, nws yuav raug coj mus rau hauv daim ntawv siv lead ua ntawm cov hmoov. Rau txoj kev loj hlob ntawm N-type crystals, qhov tsis sib xws ntawm cov tshuaj N2 hauv cov hmoov ua rau tsis sib xws ntawm cov siv lead ua thiab txawm tias hloov pauv hauv daim ntawv siv lead ua. Cov ntsiab lus nitrogen ntawm cov hmoov synthesized tom qab hydrogen tau qhia yog tsawg heev. Qhov no yog vim qhov ntim ntawm hydrogen molecules me me. Thaum N2 adsorbed nyob rau hauv cov pa roj carbon hmoov thiab silicon hmoov yog rhuab thiab decomposed los ntawm qhov chaw, H2 tag nrho diffuses rau hauv qhov sib txawv ntawm cov hmoov nrog nws me me ntim, hloov txoj hauj lwm ntawm N2, thiab N2 khiav tawm ntawm lub crucible thaum lub sij hawm lub tshuab nqus tsev, ua tiav lub hom phiaj ntawm kev tshem tawm cov ntsiab lus nitrogen.
2.3.2 txheej txheem Synthesis
Thaum lub sij hawm synthesis ntawm silicon carbide hmoov, txij li lub vojvoog ntawm cov pa roj carbon atoms thiab nitrogen atoms zoo sib xws, nitrogen yuav hloov cov pa roj carbon monoxide nyob rau hauv silicon carbide, yog li nce cov ntsiab lus nitrogen. Cov txheej txheem kev sim no siv cov txheej txheem ntawm kev qhia H2, thiab H2 reacts nrog carbon thiab silicon ntsiab hauv synthesis crucible los tsim C2H2, C2H, thiab SiH gases. Cov ntsiab lus carbon cov ntsiab lus nce los ntawm kev xa mus rau theem roj, yog li txo cov pa roj carbon monoxide. Lub hom phiaj ntawm kev tshem tawm nitrogen yog tiav.
2.3.3 Txheej txheem keeb kwm yav dhau los tswj cov ntsiab lus nitrogen
Graphite crucibles nrog porosity loj tuaj yeem siv los ua C qhov chaw ntxiv kom nqus Si vapor hauv cov roj theem Cheebtsam, txo Si hauv cov roj theem Cheebtsam, thiab yog li nce C / Si. Nyob rau tib lub sijhawm, graphite crucibles kuj tuaj yeem cuam tshuam nrog Si cua los tsim Si2C, SiC2 thiab SiC, uas yog sib npaug rau Si cua nqa C qhov chaw los ntawm graphite crucible rau hauv qhov chaw loj hlob, nce C ratio, thiab kuj nce carbon-silicon ratio. . Yog li ntawd, qhov sib piv ntawm carbon-silicon tuaj yeem nce ntxiv los ntawm kev siv graphite crucibles nrog cov porosity loj, txo cov pa roj carbon monoxide, thiab ua tiav lub hom phiaj ntawm kev tshem tawm nitrogen.
3 Kev tshuaj xyuas thiab tsim cov txheej txheem siv lead ua hmoov hmoov synthesis
3.1 Cov ntsiab lus thiab tsim cov txheej txheem synthesis
Los ntawm txoj kev tshawb fawb saum toj no hais txog kev tswj hwm ntawm qhov loj me, siv lead ua daim ntawv thiab cov ntsiab lus nitrogen ntawm cov hmoov synthesis, tau npaj cov txheej txheem synthesis. High-purity C hmoov thiab Si hmoov raug xaiv, thiab lawv sib npaug sib xyaw thiab thauj mus rau hauv graphite crucible raws li silicon-carbon piv ntawm 1.05. Cov txheej txheem cov kauj ruam yog muab faib ua plaub theem:
1) Cov txheej txheem denitrification kub qis, nqus mus rau 5 × 10-4 Pa, tom qab ntawd qhia cov hydrogen, ua rau lub chamber siab txog 80 kPa, tuav rau 15 min, thiab rov ua plaub zaug. Cov txheej txheem no tuaj yeem tshem tawm cov ntsiab lus nitrogen ntawm cov hmoov carbon thiab silicon hmoov.
2) Cov txheej txheem kub-kub denitrification, nqus mus rau 5 × 10-4 Pa, tom qab ntawd cua sov rau 950 ℃, thiab tom qab ntawd qhia cov hydrogen, ua rau lub chamber siab txog 80 kPa, tuav rau 15 min, thiab rov ua plaub zaug. Cov txheej txheem no tuaj yeem tshem tawm cov ntsiab lus nitrogen ntawm cov hmoov carbon thiab silicon hmoov, thiab tsav cov nitrogen hauv tshav kub.
3) Kev sib xyaw ua ke ntawm cov txheej txheem kub qis, tshem tawm mus rau 5 × 10-4 Pa, tom qab ntawd kub rau 1350 ℃, khaws cia rau 12 teev, tom qab ntawd qhia hydrogen kom lub chamber siab txog 80 kPa, khaws cia rau 1 teev. Cov txheej txheem no tuaj yeem tshem tawm cov nitrogen volatilized thaum lub sijhawm txheej txheem synthesis.
4) Kev sib xyaw ua ke ntawm cov txheej txheem kub kub, sau nrog qee qhov roj ntim qhov sib piv ntawm cov purity hydrogen thiab argon sib xyaw roj, ua rau lub chamber siab txog 80 kPa, nce qhov kub ntawm 2100 ℃, khaws cia rau 10 teev. Cov txheej txheem no ua tiav qhov kev hloov pauv ntawm silicon carbide hmoov los ntawm β-SiC rau α-SiC thiab ua kom tiav kev loj hlob ntawm cov khoom siv lead ua.
Thaum kawg, tos kom lub chamber kub kom txias rau chav tsev kub, sau rau atmospheric siab, thiab tshem tawm cov hmoov.
3.2 Powder post-processing txheej txheem
Tom qab cov hmoov yog synthesized los ntawm cov txheej txheem saum toj no, nws yuav tsum tau ua tom qab ua kom tshem tawm cov pa roj carbon dawb, silicon thiab lwm yam hlau impurities thiab tshuaj ntsuam cov particle loj. Ua ntej, cov hmoov synthesized yog muab tso rau hauv lub pob zeb rau crushing, thiab crushed silicon carbide hmoov yog muab tso rau hauv ib tug muffle furnace thiab rhuab mus rau 450 ° C los ntawm oxygen. Cov pa roj carbon dawb hauv cov hmoov yog oxidized los ntawm tshav kub los tsim cov pa roj carbon dioxide uas khiav tawm ntawm lub chamber, yog li ua tiav qhov kev tshem tawm ntawm cov pa roj carbon monoxide. Tom qab ntawd, cov kua qaub ntxuav yog npaj thiab muab tso rau hauv silicon carbide particle tu tshuab rau kev ntxuav kom tshem tawm cov pa roj carbon, silicon thiab cov hlau tsis huv uas tau tsim thaum lub sij hawm tsim cov txheej txheem synthesis. Tom qab ntawd, cov kua qaub seem yog ntxuav hauv dej ntshiab thiab qhuav. Cov hmoov qhuav yog tshuaj ntsuam xyuas hauv vibrating npo rau particle loj xaiv rau kev loj hlob siv lead ua.
Post lub sij hawm: Aug-08-2024